A fixing device includes a heating roller and a pressing unit. The pressing unit includes a pressurizing belt and a pressurizing roller. The outer circumferential surface of the pressurizing roller is covered with a rubber layer. The pressing unit presses a sheet against the heating roller to thereby thermally fix toner to the sheet.
In the fixing device, if the rubber layer of the pressurizing roller is deteriorated by aging, in some case, a nip width increases, creases occur on the sheet, and the sheet tilts.